Officials are probing how a 51-year-old highway bridge came to collapse in the Italian port city of Genoa yesterday, killing at least 26 people and injuring 16 others as it sent dozens of vehicles tumbling into a heap of concrete and twisted steel.

The 30-year-old victim's body was found with her pants pulled partially down.

A source said Lewis had a number of scratched on him when he went home after the attack occurred. He reportedly lied to his mum about how he got them before later confessing to authorities.

However, he denied sexually assaulting Ms Vetrano.

Mr Vetrano and his wife raised hunderds of thousands of dollars overnight when they launched an online campaign to catch the "vicious animal" who murdered their daughter. (Instagram) ()

A source at Martin De Porres High School, which Lewis previously attended told the NY Post the former student told a teacher’s aide he "wanted to bring a knife to school to stab all the girls" when he was 15 in 2011.

The 20-year-old's father Richard Lewis denies his son was responsible for Ms Vetrano's death.